Study On Phytoremediation Of Aniline Polluted Water By Aquatic Plants

Aniline is a kind of organic pollutant whose toxicity is immense and pollution rang is vast in some domestic and industrial sewage.There are obvious disadvantages in traditional treatments by physical,chemical and biological methods.In this paper,a phytoremediation process was used to repair the water body polluted by aniline.The research was involved in the plant selection and the operational conditions optimization.It is expected to develop an efficient,cost-effective,continuous degrading strategy to restore the polluted waterbody and to beautify the landscape.The results indicated that alocasia macrorrhiza showed high removal efficiency of TN,TP,COD and aniline compared with other submerged plants(Canna indica L,Alocasia macrorrhizos,Thalia dealbata),floating plants(Water hyacinth,Lysimachia christinae,Lemna minor)and emerged plants(Ceratophyllum demersum,Vallisneria(Lour)hara,Hydrilla verticallate)and thus alocasia macrorrhiza was selected as the target plant.The optimal conditions were achieved as temperature of 28?,pH of 6.0 and the initial concentration of aniline of 38 mg/L by means of single factor test and orthogonal test.It was found that 99.6% of aniline coule be removal and alocasia macrorrhiza grew well in the phytoremediation process.Moreover,the removal efficiently of COD,TN,TP and aniline by plant and microorganism was studied to obtain the removal mechanism of aniline.It was indicated that the main removal is dependent on enrichment of plant.The absorbtion is mainly focus on the root of alocasia macrorrhiza,a portion would be migrated to the stem and leaf.The absorbed aniline was removed from plant by metbohzee.The maximum tolerance of alocasia macrorrhiza to aniline was studied by replacing the water periodically.When the concentration of aniline was 40 mg/L and the water was replaced every 4 days.alocasia macrorrhiza showed the normal state within 3cycles,they would show persecution symptoms in 7 cycles.It also showed that plant had a good adaptability to low concentration of aniline and could show normal state for a long time.The lifted concentration would do harm to them and shorten their servicing.The phytoremediation process was further used for the treatment of nitrobenzene wastewater.The results demonstrated that the medium and high concentration nitrobenzene would damage the aquatic plants immensely and make the root rotten.When the concentration of nitrobenzene was below to 5 mg/L,the treatment efficiency increased dramatically and its temoval efficient researched 99%.The running cycle would last 4 days constantly with changing the nitrobenzene wastewater every day.Additionally,It would take 3 weeks,5 weeks and 8 weeks respectively for the mild injury,moderate injury and severe injury to restore their normal states and aniline was not be tested in their stem and leves.The removed alocasia macrorrhiza would be further reused in the aquatic phytoremediation cultural medium,respectively.The recovered alocasia macrorrhiza would be further reused in the aquatic phytoremediation.